Question: A goblet contains $4$ red marbles, $3$ green marbles, and $9$ blue marbles. If a marble is randomly chosen, what is the probability that it is not red?
Solution: There are $4 + 3 + 9 = 16$ marbles in the goblet. There are $4$ red marbles. That means $16 - 4 = 12$ are not red. The probability is $ \frac{12}{16} = \dfrac{3}{4}$.